System and method for controlling erosion of components during well treatment

ABSTRACT

A technique is provided for use in treating one or more well zones by directing a treatment fluid downwardly through a delivery tube and then outwardly through one or more nozzles into a desired well zone. The treatment fluid is delivered downhole to the desired well zone and at least a portion of that fluid is directed laterally outward from the well treatment completion through the one or more nozzles. Each nozzle comprises a material that protects both the nozzle and proximate portions of the delivery tube from detrimental erosion due to the passage of treatment fluid.

BACKGROUND

Many types of well treatments are performed by a variety of completions.The well treatments may involve sand control operations in which gravelladen slurry is delivered downhole to a desired well zone to be gravelpacked. In many applications, the gravel slurry can create significanterosion of completion components against which or through which theslurry is flowed to the desired well zone. In some gravel packoperations, the slurry is delivered down a tube, such as a shunt tube,and forced outwardly through laterally oriented nozzles. The flowingslurry can create component erosion at various contact points along thetube and nozzles. If the nozzles or tube become sufficiently eroded, theexiting slurry is not properly directed away from the completioncomponents, e.g. sand screens, to create a properly functioning gravelpack.

Existing nozzles are generally constructed as a stainless steel tube,but rapidly flowing slurry can erode the stainless steel tube as well asthe outlet opening of the delivery tube through which slurry flows tothe nozzle. The erosion is currently minimized by pumping at slowerrates to ensure gravel velocities are below the critical velocitycausing erosion of the component. Attempts also have been made tominimize erosion by installing a carbide tube within the stainless steeltube. However, the carbide tube has not prevented erosion at the base ofthe nozzle and at the delivery tube wall proximate the nozzle entry. Ifthe erosion leads to slurry bypassing the nozzle, the slurry is then nolonger properly directed away from the completion, e.g. away from thefiltration surface, which can result in erosion of the filtrationsurface and failure of the well completion.

SUMMARY

In general, the present invention provides a system and method for usewith a completion in treating one or more well zones. The treatmentinvolves directing a treatment fluid downwardly through a delivery tubeand then outwardly through one or more nozzles into a desired well zone.A slurry or other treatment fluid is delivered downhole to the desiredwell zone and at least a portion of that fluid is directed laterallyoutward from the well treatment completion through the one or morenozzles. Each nozzle is uniquely designed to protect both the nozzle andproximate portions of the delivery tube from erosion that woulddetrimentally affect the well treatment operation.

BRIEF DESCRIPTION OF THE DRAWINGS

Certain embodiments of the invention will hereafter be described withreference to the accompanying drawings, wherein like reference numeralsdenote like elements, and:

FIG. 1 is a front elevation view of a completion assembly for use in awell treatment operation, according to an embodiment of the presentinvention;

FIG. 2 is a cross-sectional view of an embodiment of a nozzle coupled toa fluid delivery tubing, according to an embodiment of the presentinvention;

FIG. 3 is a cross-sectional view of another embodiment of a nozzlecoupled to a fluid delivery tubing, according to an embodiment of thepresent invention;

FIG. 4 is a cross-sectional view of another embodiment of a nozzlecoupled to a fluid delivery tubing, according to an embodiment of thepresent invention;

FIG. 5 is a cross-sectional view of another embodiment of a nozzlecoupled to a fluid delivery tubing, according to an embodiment of thepresent invention;

FIG. 6 is a cross-sectional view of another embodiment of a nozzlecoupled to a fluid delivery tubing, according to an embodiment of thepresent invention;

FIG. 7 is a cross-sectional view of another embodiment of a nozzlecoupled to a fluid delivery tubing, according to an embodiment of thepresent invention;

FIG. 8 is a cross-sectional view of another embodiment of a nozzlecoupled to a fluid delivery tubing, according to an embodiment of thepresent invention;

FIG. 9 is a cross-sectional view of another embodiment of a nozzlehaving an insert plate coupled to a fluid delivery tubing, according toan embodiment of the present invention;

FIG. 10 is a cross-sectional view of another embodiment of a nozzlehaving an insert plate coupled to a fluid delivery tubing, according toan embodiment of the present invention;

FIG. 11 is a cross-sectional view of another embodiment of a nozzlecoupled to a fluid delivery tubing, according to an embodiment of thepresent invention;

FIG. 12 is a cross-sectional view of another embodiment of a nozzlecoupled to a fluid delivery tubing, according to an embodiment of thepresent invention;

FIG. 13 is a cross-sectional view of another embodiment of a nozzlecoupled to an interior surface of a fluid delivery tubing, according toan embodiment of the present invention;

FIG. 14 is a cross-sectional view of another embodiment of a nozzlecoupled to a fluid delivery tubing, according to an embodiment of thepresent invention;

FIG. 15 is a cross-sectional view of another embodiment of a nozzlecoupled to a fluid delivery tubing, according to an embodiment of thepresent invention;

FIG. 16 is a cross-sectional view of another embodiment of a nozzlecoupled to a fluid delivery tubing, according to an embodiment of thepresent invention;

FIG. 17 is a cross-sectional view of another embodiment of a nozzlecoupled to a fluid delivery tubing, according to an embodiment of thepresent invention;

FIG. 18 is a cross-sectional view of another embodiment of a nozzlecoupled to a fluid delivery tubing, according to an embodiment of thepresent invention;

FIG. 19 is a cross-sectional view of another embodiment of a nozzlecoupled to a fluid delivery tubing, according to an embodiment of thepresent invention; and

FIG. 20 is a cross-sectional view of another embodiment of a nozzlecoupled to a fluid delivery tubing, according to an embodiment of thepresent invention.

DETAILED DESCRIPTION

In the following description, numerous details are set forth to providean understanding of the present invention. However, it will beunderstood by those of ordinary skill in the art that the presentinvention may be practiced without these details and that numerousvariations or modifications from the described embodiments may bepossible.

The present invention generally relates to a well system that can beused for well treatment operations, such as sand control operations. Thewell system is designed to deliver a well treatment fluid, e.g. a gravelslurry, downhole to a desired well zone. The well treatment fluid isdelivered through a tubing, such as a shunt tube, and then routedlaterally outward through one or more nozzles. Each nozzle comprises aninsert region that forms a flow path for the well treatment fluid. Theinsert region is designed to control erosion with respect to both thenozzle and the tubing portion proximate the nozzle.

Referring generally to FIG. 1, one embodiment of a well system 30 isillustrated. In this embodiment, well system 30 comprises a completionassembly 32 deployed in a wellbore 34. The wellbore 34 is drilled into asubsurface formation 36 having at least one well zone 38 to be treated,e.g. gravel packed. Wellbore 34 extends downwardly from a surfacelocation 40, such as a surface of the earth or a subsea surfacelocation.

Completion assembly 32 comprises a treatment string 42 that can be usedto perform the treatment of well zone 38. A well treatment fluid isdelivered downhole through completion assembly 32 and along treatmentstring 42 via one or more delivery tubes or tubular members 44. Thetreatment fluid is directed radially or laterally outward from tubularmembers 44 via one or more nozzles 46. In the example illustrated,tubular members 44 comprise one or more shunt tubes 48 that route thetreatment fluid along treatment string 42. If the well treatment is asand control treatment, e.g. a gravel packing treatment, treatmentstring 42 comprises one or more screens 50, and the treatment fluidcomprises a gravel slurry, as known to those of ordinary skill in theart. Also, one or more well zones 38 can be isolated by appropriatelyplaced packers 52.

Nozzles 46 are designed to redirect the well treatment fluid flowingthrough the tubular members 44 and ordinarily are susceptible to wear,particularly with abrasive treatment fluids such as gravel slurry.Several embodiments of nozzles 46 that are designed to eliminate or atleast control erosion caused by the treatment fluid are describedherein. One embodiment is illustrated in FIG. 2 as mounted to one of thetubular members 44, e.g. shunt tube 48, that deliver a well treatmentfluid downhole, as indicated by arrows 54. At least a portion of thewell treatment fluid is redirected laterally outward through the nozzle46.

In this embodiment, nozzle 46 comprises an insert region 56 having aflow passage 58 through which the well treatment fluid flows laterallyoutward from an interior 60 of tubular member 44. Insert region 56 isformed from an erosion resistant material which may be a hardenedmaterial, such as a carbide material. For example, the insert region 56can be formed of tungsten carbide, a ceramic material, or Stellite. Theoutward flow of well treatment fluid is enabled by an opening 62 formedthrough a wall 64 of tubular member 44. Insert region 56 comprises acorresponding end region 66 sized to fit within opening 62 and extendthrough wall 64. By extending the material of insert region 56 throughwall 64, protection is provided both for nozzle 46 and for tubularmember 44 in the region where well treatment fluid is routed into nozzle46. In the embodiment illustrated, insert region 56 extends into opening62 until it is generally flush with an interior surface 68 of tubularmember 44.

As illustrated, insert region 56 further comprises a shoulder 70positioned to abut a wall 64 and prevent the insert region 56 frommoving inwardly into tubular member 44. A retaining housing 72 ispositioned over insert region 56 on the exterior side of tubular member44 to secure insert region 56 and the overall nozzle 46 with respect totubular member 44. By way of example, retaining housing 72 may be formedfrom a conventional nozzle material, such as a steel material, that iswelded or otherwise fastened to wall 64 of tubular member 44. In thisembodiment, retaining housing 72 comprises an opening 74 through whichthe well treatment fluid is discharged from flow passage 58. It shouldbe noted the insert region 56 can be formed as a separable component oras a component adhered to or otherwise combined with retaining housing72. The insert region 56 also can be coated onto or otherwise applied toretaining housing 72.

Another embodiment of nozzle 46 is illustrated in FIG. 3. In thisembodiment, the components are similar to the components described withreference to FIG. 2, except that corresponding end region 66 extendsinwardly beyond a flush position with interior surface 68 and into theinterior 60 of tubular member 44. By extending the insert region 56 intointerior 60, the nozzle 46 is able to “grab” well treatment fluidpassing through tubular member 44 and redirect the fluid into nozzle 46.By extending the erosion resistant material of insert region 56 intointerior 60, both nozzle 46 and tubular member 44 proximate opening 62are protected from material erosion.

The configuration of insert region 56 can be adjusted to combat materialerosion in areas experiencing the greatest susceptibility to erosion andloading. As illustrated in FIG. 4, for example, insert region 56 isformed eccentrically such that a lower wall portion 76 of correspondingend region 66 is thicker, at least where it extends into interior 60.The thicker erosion resistant material is located on the sideexperiencing the greatest potential for erosion and loading with thisparticular nozzle configuration.

In another embodiment, insert region 56 comprises a laterally outwardend 78 sized to extend through opening 74 of retaining housing 72. Theoutward end 78 of insert region 56 further protects retaining housing 72from erosion at the point where well treatment fluid is discharged fromnozzle 46. This type of laterally outward end 78 can be utilized with anumber of the nozzle embodiments described herein. For example,positioning outward end 78 through housing opening 74 can be utilizedwith a nozzle insert region having a concentric (as opposed toeccentric) corresponding end region 66, as illustrated best in FIG. 6.

An alternative approach to controlling erosion that may occur at thenozzle tip is illustrated in the embodiment of FIG. 7. In thisembodiment, outward end 78 does not extend through housing opening 74;however the insert region 56 is blocked from moving outwardly withrespect to retaining housing 72 by an outer shoulder 80. Outer shoulder80 is formed in insert region 56 to abut a corresponding shoulder 82 ofretaining housing 72. Thus, even if retaining housing 72 erodes atopening 74, outer shoulder 80 prevents the outward movement of insertregion 56.

Insert region 56 also can be retained within retaining housing 72 byfastening insert region 56 to an interior of retaining housing 72 by anappropriate fastening mechanism 84, as illustrated in FIG. 8. Examplesof fastening mechanism 84 comprise an adhesive, threads, a weldment, abrazed joint, a press fit or another suitable mechanism for a fixinginsert region 56 to the surrounding retaining housing 72. This enablesthe construction of retaining housing 72 in a simple form, such as theillustrated tubular housing. Fastening mechanism 84 also enables thecreation of a variety of nozzle outlets 86 with the erosion resistantmaterial of insert region 56.

In some applications, further protection of tubular member 44 fromerosion can be provided by forming insert region 56 has a two-partmember, as illustrated in FIG. 9. The two-part insert region 56comprises a housing portion 88 within retaining housing 72 and a plateportion 90 that replaces a portion of wall 64 of tubular member 44. Thetwo-part insert can be formed as completely separate components or asattached or combined components. In the embodiment illustrated, plate 90is naturally held in place by the tube walls on the interior side and bya retaining housing plate 92 on the exterior side. Housing plate 92 canbe attached and sealed to wall 64 by welding or other appropriatepermanent attachment mechanisms. Plate 90 comprises an opening 94 thatforms the initial portion of flow passage 58 through which welltreatment fluids flow. In this embodiment, housing portion 88 is formedas a simple hollow shaft trapped within retaining housing 72.

A similar embodiment is illustrated in FIG. 10. In the embodiment ofFIG. 10, plate 90 is a circumferential plate that extends around thecircumference of tubular member 44, effectively separating tubularmember 44 into an upper section 96 and a lower section 98. Retaininghousing plate 92 also extends circumferentially around tubular member 44in a manner that holds circumferential plate 90 in place between tubularsections 96 and 98. This style of plate 90 provides erosion protectionacross the entire tubular member in the vicinity of nozzle 46.

Another embodiment of nozzle 46 is illustrated in FIG. 11. In thisembodiment, the insert region 56 comprises an enlarged block 100 havingflow passage 58 therethrough. The corresponding section of tube wall 64is removed to accommodate enlarged block 100 which extends through wall64 at least to a point where the block is substantially flush withinterior surface 68 of tubular member 44. The enlarged block 100 can besecured within wall 64 by an appropriate adhesive, weldment or othersuitable fastener. Because of the enlarged size of block 100, the blockmay be designed to undergo a controlled erosion in which the gravel packor other well treatment is completed before a critical amount of thenozzle material is eroded. Accordingly, this type of nozzle 46 can bemade from a cheaper material due to the ability to allow the controllederosion. For example, controlled erosion can be achieved with a steelmaterial, e.g. stainless steel, a plastic material, or other suitablematerials that enable the controlled erosion.

As illustrated in FIG. 12, enlarged block 100 also may be attached tothe exterior of tubular member 44 by a suitable attachment mechanism,e.g. weldment, adhesive, brazing, or other suitable fastener. In thisembodiment, tubular wall opening 62 is protected by the size of block100. In other words, even though the wall of tubular member 44 mayerode, the erosion does not expand beyond block 100 prior to completionof the gravel pack or other well treatment. Effectively, the size andposition of enlarged block 100 of nozzle 46 controls the erosion andeliminates or reduces the potential to create unwanted openings throughwhich the slurry or other treatment fluid can flow.

In another alternate embodiment, insert region 56 is retained frommoving away from tubular member 44 by an internal flange 102 positionedalong interior surface 68 of tubular member 44, as illustrated in FIG.13. This same insert region 56 can be prevented from moving inwardlyinto tubular member 44 by a retaining housing or other suitablefastening mechanism. Examples of fastening methods comprise adhering,welding, brazing, and the use of external threads and a retaining nut.

Other embodiments of nozzle 46 are designed to control the flow ofslurry or other treatment fluid as it exits the nozzle, as illustratedin FIGS. 14 and 15. For example, the shape and size of flow passage 58can be adjusted to change the velocity of the particles within thetreatment fluid. In the embodiment illustrated in FIG. 14, for example,the flow passage 58 is designed to slow particle velocities exitingnozzle 46 to reduce the likelihood of eroding the filter or otherhardware in the vicinity of nozzle 46. As illustrated, the height offlow passage 58 increases as the flow passage transitions from an inlet104 to an exit 106. In this particular example, the width of flowpassage 58 is substantially constant, however other flow passage designscan be utilized to further control the flow of treatment fluid.Furthermore, the expanding flow passage 58 is illustrated as formed inthe enlarged block 100 positioned either through wall 64 (FIG. 14) orattached along the exterior of wall 64 (FIG. 15). However, theconfiguration of flow passage 58 can be changed to achieve desired flowcharacteristics for the other embodiments of nozzle 46.

In some applications, nozzle 46 can be constructed by forming insertregion 56 as a simple tube 108 inserted in through opening 62 of wall 64and into interior 16 of tubular member 44, as illustrated in FIG. 16.Again, this simple type of insert protects both nozzle 46 and tube wall64 from erosion, because the erosion resistant insert region extendsthrough the tubular member wall. The nozzle tube 108 can be attached totubular member 44 by a suitable fastening method, including adhering,press fitting, threading, welding and brazing. Additionally, the flowpassage 58 can be routed in a generally linear direction, as illustratedin FIG. 16, or along a curvilinear path, as illustrated in FIG. 17.Curvilinear flow paths also can be incorporated into other embodimentsof nozzle 46.

Nozzles 46 also can be designed to change their spray pattern over time,as illustrated by the embodiments of FIGS. 18 and 19. The design andmaterial of the nozzle is selected to undergo a controlled erosionhaving no deleterious effects on the nozzle or the tubular member 44that would interfere with the desired well treatment. In the embodimentillustrated in FIG. 18, nozzle 46 is attached to an exterior of tubularmember 44 over opening 62 via a suitable fastening method, e.g.adhering, welding, brazing. The flow passage 58 is generally arcuate,curving downwardly via an outer lip 110. Initially, the gravel slurry orother treatment fluid is sprayed in a downward direction. However, aslip 110 erodes in a desired, controlled manner, the angle of spray fansupwardly and outwardly to provide a better fill from the bottom up. Inmany applications, lip 110 is designed so the spray angle does not moveupwardly beyond a desired angle, e.g. 45°.

The use of a nozzle that undergoes controlled erosion to selectivelychange the spray pattern can be incorporated with a number of the nozzleembodiments described herein. Another example is illustrated in FIG. 19,in which the nozzle 46 comprises an end region 112 sized to fit withinwall opening 62. The end region 112 can be designed to extend to alocation flush with interior surface 68 or to extend further into theinterior 60 of tubular member 44.

Another embodiment of nozzle 46 incorporates a spacer ring 114, asillustrated in FIG. 20. The spacer ring 114 allows the hardened materialof insert region 56 to be formed with a generally perpendicular shoulder116. Perpendicular shoulder 116 is arranged to abut spacer ring 114 atan outlying end, while the opposite end of spacer ring 114 abuts thewall 64 of tubular member 44. Thus, shoulder 116 and spacer ring 114prevent insert region 56 from moving inwardly into tubular member 44.Retaining housing 72 is positioned over both insert region 56 and spacerring 114. In the embodiment illustrated, insert region 56 furthercomprises a reduced diameter section 118 that fits within spacer ring114. The flow passage 58 extends generally axially through the reduceddiameter section 118 and past shoulder 114 until it meets opening 74 ofretaining housing 72.

The unique nozzles 46 can be used with a variety of completionassemblies and service tools where it is necessary or desirable tocontrol or eliminate erosion that would otherwise be caused by the welltreatment fluid. Furthermore, the nozzles can be used in many sandcontrol/gravel packing operations practiced in a variety ofenvironments. However, the nozzles also can be used in other treatmentoperations. The size, shape and location of each nozzle 46 can beadjusted according to the needs of a specific well treatment operation.Similarly, the materials used to form each nozzle 46 can be selectedaccording to the environment, the type of well treatment fluid, thedesire to eliminate or otherwise control the erosive effects of the welltreatment fluid, and other operational parameters. The shunt tubes orother fluid delivery tubes also can be designed and routed according tothe treatment operation and the treatment equipment used in theoperation.

Accordingly, although only a few embodiments of the present inventionhave been described in detail above, those of ordinary skill in the artwill readily appreciate that many modifications are possible withoutmaterially departing from the teachings of this invention. Suchmodifications are intended to be included within the scope of thisinvention as defined in the claims.

1. A system to facilitate a gravel packing operation, comprising: ashunt tube through which a gravel slurry is directed; and a nozzlecoupled to the shunt tube to direct a portion of the gravel slurrylaterally outward from the shunt tube, the nozzle having a hardenedinsert region forming a flow path and extending through a wall of theshunt tube.
 2. The system as recited in claim 1, wherein the hardenedinsert region extends through the wall until it is flush with the insidediameter of the shunt tube.
 3. The system as recited in claim 1, whereinthe hardened insert region extends through the wall and into an interiorof the shunt tube.
 4. The system as recited in claim 1, wherein thenozzle further comprises a retaining housing to hold the hardened insertregion against the wall of the shunt tube.
 5. The system as recited inclaim 4, wherein the hardened insert region comprises a shoulderpositioned to prevent movement of the hardened insert region into theshunt tube.
 6. (canceled)
 7. The system as recited in claim 1, whereinthe hardened insert region is secured directly to the wall of the shunttube.
 8. The system as recited in claim 1, wherein the hardened insertregion comprises a separate plate positioned in a corresponding openingformed in the wall, of the shunt tube.
 9. (canceled)
 10. The system asrecited in claim 1, wherein the hardened insert region is retained withrespect to the shunt tube from an interior of the shunt tube.
 11. Thesystem as recited in claim 1, wherein the flow path within the nozzle iscurvilinear.
 12. A method to facilitate a well treatment, comprising:flowing a slurry into a wellbore region through a delivery tube;diverting at least a portion of the slurry laterally through a nozzle;and protecting both the nozzle and the delivery tube from erosion withan insert located along a flow path into and through the nozzle.
 13. Themethod as recited in claim 12, wherein protecting comprises extendingthe insert through a wall of the delivery tube and into an interior ofthe delivery tube.
 14. The method as recited in claim 12, whereinprotecting comprises extending the insert until the insert is generallyflush with a wall surface defining an internal diameter of the deliverytube.
 15. The method as recited in claim 12, further comprising holdingthe insert at a desired position with a retaining housing. 16.(canceled)
 17. (canceled)
 18. The method as recited in claim 12, furthercomprising securing the nozzle to an interior surface of the deliverytube.
 19. The method as recited in claim 12, further comprising securingthe nozzle at an opening formed through the delivery tube.
 20. Themethod as recited in claim 12, wherein protecting comprises forming aportion of the insert as a plate fitted within an opening formed in thedelivery tube.
 21. The method as recited in claim 12, further comprisingforming the nozzle to erode in a predetermined manner.
 22. The method asrecited in claim 12, further comprising providing the nozzle with acurvilinear flow path.
 23. A method, comprising: forming a nozzle with amaterial that limits the normal erosion otherwise incurred duringpassage of a gravel slurry through the nozzle; and fastening the nozzleover a side opening of a tubular member through which the gravel slurryis delivered such that the material also protects the tubular memberfrom erosion proximate the side opening.
 24. The method as recited inclaim 23, wherein forming comprises forming the nozzle with a retaininghousing and an insert held at least partially within the retaininghousing, the insert being formed of the material.
 25. The method asrecited in claim 23, wherein forming comprises forming the nozzle toextend through the side opening and to protrude into an interior of thetubular member.
 26. The method as recited in claim 23, wherein formingcomprises forming the nozzle with a separate plate sized to fit withinthe side opening.
 27. A system, comprising: a nozzle for use indirecting an erosive fluid from a delivery tube and into a wellboreregion, the nozzle having an insert formed of a material to controlerosion of both the nozzle and the delivery tube, the insert beingpositioned to extend through a wall of the delivery tube to at least aninside diameter of the delivery tube upon attachment of the nozzle tothe delivery tube.
 28. The system as recited in claim 27, wherein thenozzle comprises a retaining housing surrounding the insert.
 29. Thesystem as recited in claim 27, wherein the nozzle is formed from amaterial that erodes in a controlled manner to change a nozzle spraypattern.